Radiator



June 7, 1932. J. M` HARRISON RADIATOR Filed March 2, 1929 W WW ` mffuYc/j.

Patented June 7, 1932 UNITED ,STA

Y JAMES 1yr. HARRISON, on cniiivnniilvn,` omo RADIATOR Application led March 2, 1929. Serial No. 344,038.

`This invention relates to heat exchange devices, and more particularly to radiators adapted to be used with direct and indirect radiation systems. Y

54 Wherefluid is brought into contact with heating surfaces for the purpose of heating the iiuid, it is generally known that a layer or film of fluid of indefinite thickness, which is in direct contact with the heating surface tends to cling or adhere to this surface and to form a non-conductive covering lwhich' prevents heat from being readily transferred to the layers of fluid which are more remote from the heating surface. This adherence i5 between the layer of Huid and the heating surface appears to be due largely to frictional resistance between .the fluid and the surface, lwhich* causes this layer offluid to lag while the more remote layers of fluid pass over this 1ayer without being heated to the desired extent. The result of this phenomenon is a material decrease in the efficiency of a heat exchanger so that it becomes necessary to use large areas of heating surface to heat a fluid to a desired temperature. I have found that by breaking up or dispelling thissubstantially non-conductive layer or film, and causing all of the fluid to be heated to repeatedly comeinto direct contact with the heating surfaces, the eiiiciencyzof a heat exchanger will be greatly increased.

It is an object of this invention to provide a novel form of heat exchanger in which'the rate of transfer of heat to the fluid to'be heated will begreatly increased.

The invention may be further briefly suinmarized as consisting in certain novel arrangements'and combinations of parts hereinafter described and set out in theappended claims. In the accompanying sheet of drawing forming a part of this application,

Fig. 1f is a perspectiveview showingV one form of heat exchanger constructed accord'- ing to my invention; 5 1 Fig. 2 is a cross-sectional view of th heat exchanger Vshown in Fig. l; i

. Fig. 3 is an end elevational'view of another form of heat exchanger embodying my invention; .i f

lF ig. l is a Vfragmentary side elevational View of the heat exchanger shown in Fig. 3;

Figs. 5 and 6 are fragmentary views illustrating the principle of my invention;

Figs. 7, 8 and 9 are' fragmentary views showing dierent forms of screens which may be used in carrying out my invention;- and Fig. lO is a fragmentary view illustrating one manner of spacing the screeny between the heating elements.

rReferring now in detail to the drawing in Fig- ,1 of which I show my invention e1nbodied in a heat exchanger of the type commonly used in indirect radiation systems. This heatexchanger comprises a casing 15, within which is arranged a group of spaced parallel heating elements 16. These elements may be of any desired shape, but are preferably hollow and lprovided with flat parallel heating surfaces 16, which will be termed prime heating surfaces.

For heating the elements they may be supplied with steam orother heating medium from a header 17 to which they are connected. A fan V-or blower 18 may be connectedto the casing for forcing air or other fluid to be heated: through the passages formed between adjacent heating elements. A header 19may be connected to theheating elements for collecting and carrying away the heating mediuin which passes through the heat exchanger.

To increase the rate transfer of'heat to the fluid to be heated, Iprovide screens or auxiliary heating surfaces-20 whichV are held-between the opposed prime heating lsurfaces 16 Vof adjacent parallel elements `16 in any convenient way. These screens or 'auxiliary heating surfaces are preferably formed, as

best shownin Figs. 5, 6 and 7, by stamping or punching sheets of metal to provide-rows of outstanding lugs 21. As fiuid passes through the heat exchanger these'lugs act as deflectors which direct thekfluid against the prime heating surfaces. 'When the fluid deflected by the lugsimpinges'againstthe primeheating surfaces, it acts to dispel or break up the layer or film. of iiuid whichtends to cling to Vthese heating surface-s. During the passage,

of fluid through theheat exchanger, its direction of flow is repeatedly changed by the lugs,

thus bringing all of the Huid into direct contact with the prime heating surfaces thereby permitting the Ytransfer of the maximum amount of heat t the fluid by convection. In additionto heating the fluid by causing it to impinge against the prime heating surfaces, it is alsoheated by its contact with the auxiliary heating surface 2 0, which has been vheated by energy radiated from the prime heating surfaces. Thus it will be seen that the screens greatly facilitate-the heating'v of the fluid by serving as deflectors for causing the fluid to come into direct contact with the prime heating surfaces, and also by serving as auxiliary heating surfaces which trans'- fer to the Yfluid heat which has been radiated fromj .they prime' heating surfaces.

lIn Figs. 3 and 4;, of the drawing, Ishow a radiator 22l ofthe type commonly usedvwith direct systems of radiation in which fluid to be heated is caused to flow over the heating surfaces of theradiator by the action of gravity. v'lheradiator 22 is composed of hollow sectionsv 2 3 spacedito. provide passages be- .tween adjacent sectionsnfor ther flow of the y fluid to be heated.' The end sections of radiavtor 22 are preferably provided with legs 24 which support the radiator. The customary connections are provided at each end of the radiator to permit the flow of steam or other heating fluid through the hollow sections 23. 'Ifo increase the rate 0f transfer of heat to the fluid, I provide a screen or auxiliary heating surface 24 between the opposed prime heating surfaces 23 of adjacent parallel sections 23. This auxiliary heating surface issimilar to the auxiliary heating surface 20, already described,.and`functions in the same manner except that the flow of fluidthrough the passages between thesections is caused by gravity. 'IheY Aauxiliary heating surface 24 is clamped between sections 23, or heldin place in any suitable manner, and is provided with outstanding lugs 25 which deflect the fluid against the prime heatingsurfaces so asto preventthe formation of ya layer or film of heated fiuideon these surfaces; YThe auxiliary heating-surface 424: is heated by energy radiated from the prime heating surfaces and transfers this heat to the fluid which contacts with this surface-in its passage through the heat exchanger. f

lTo clearly illustrate the principle of Vmy invention, I show in Figs. 56 and'7 the approximate position ofsuch auxiliary -heating surfaces vrelative to the prime heating surfaces, and to illustrate the manner in which the fluidi to be heated is deflected .and made to impinge againstthe prime heating surface, I have used arrows in Fig. 5 to. represent the-'approximate Vdirection of flow' Vof the fluid. As indicated by these arrows the direction of'fiow. is. repeatedly changed and'T the `fluid directed against ,the prime' heating surfacesthus preventing a layer of fluid from adhering to these surfaces and also causing all of the fluid to repeatedly come into conthe fluid to be heated against'the prime heating surfaces. As examples offdierentl kinds of auxiliary heating lsurfaces,which may. be employed in 'carrying-out my invention, I show in Fig. 8, a screen or auxiliary heating surface 26 which 'is made oflexp'anded metal,

and inFig. 9 I show-an auxiliary heating surface 29 constructed of wire screen. It is obvious thatfor spacingandholding the auxiliary heating surfaces between the prime heating surfaces any suitableY means may beY 3 used, but if desired, the screens may beprovided'witlra marginal portion 28, as shown in Fig. 8,and for spacing the screens between the prime heating surfaces'spacedflugsl27 may be formed alongy this marginal portion as shown in Figs. 8 and l0.,

It will `now be readily understood that y where auxiliary heating surfaces, such as I have shownand described, are used between prime heating surfaces, fluid flowing through the rheat exchanger between the-prime heatr ing surfaces will be heated by being deflected against the prime heating surfaces, andrwill also receive heatv from the auxiliary heating f surfaces which khave been heated by energy radiated from the primeheating surfaces. Vith this arrangement therate of transfer of heat to 'thefluid'to be heatedis increased Yto such an extent that theI area of prime heating surface may be greatly reduced, which permits a reduction in the size and weight of heat"exchangerslandl alsok results'in a savingof space. y .i

For the purpose of. illustration vI have shown and described heat exchange apparatus in which heating surfaces areadapted to be heated .by causing hot. fluids tokflow through the hollow elements, butit :should be understood that the manneriof supplying heat to the heating surfaces is not an essential feature of Vthe invention,"and heat` may be supplied to thesersurfacesinany convenilnt Vway such as by direct firing or bywaste eat..."

while I have silownana desear-.diadema variouskinds and arrangements' ofV apparatus, it shouldpbe understood 'that nIdognot limit my invention to theprecise vdetails' and arrangements shown, but :regard my invention as including such alterations and modifilll() cations as do not involve a departure from the spirit of the invention and scope of the appended claims.

Having thus described my invention, I claim:

l. In a heat exchanger, the combination of oppositely disposed heating surfaces having a passage therebetween for fluid to be heated, and means interposed between said surfaces and extending in spaced substantially parallel relation thereto, said means having angularly disposed portions for deflecting streams of said fluid against said surfaces.

2. In a heat exchanger, the ycombination of a prime heating surface, and an auxiliary heating surface extending in spaced substantially parallel relation thereto and heated by energy radiated from said prime surface, said auxiliary heating surface being provided with rows ofangularly disposed sheared vportions for deflecting lfluid heated by said auxiliary surface against said prime surface.

3. In a heat exchanger, the combination of a prime heating surface, and means for deflecting fluid against said prime heating surface, said means comprising an auxiliary heating surface extending substantially parallel with said prime surface and adapted' to be heated only by energy radiated from said prime surface.

4. In a heat exchanger, the combination Aof prime heating surfaces having a passage therebetween for fl'uid to be heated, and a screen interposed between and spaced from adjacent prime surfaces for deflecting said fluid against the latter and also forming an auxiliary heating surface y adapted to receive heat radiated from said prime surfaces and to transfer said heat to said fluid, said screen` comprising a metallic sheet having oppositely inclined deflecting portions outstanding from the surfaces thereof. y

5. In a heat exchanger, the combination of a wall for separating two streams of fluid in heat exchange relation, and means extending substantially parallel with and in spaced relation to said wall and being provided with rows of sheared angularly disposed portions for dellecting one of said fluids against said wall to thereby prevent a layer of the fluid deflected from clinging thereto.

In testimony whereof, I hereunto afix my signature.

JAMES M. HARRISON. 

